package org.tinaelle.servlet.utils.json;

/*
 * Copyright (c) 2002 JSON.org
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
 * documentation files (the "Software"), to deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the
 * Software.
 * 
 * The Software shall be used for Good, not Evil.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

import java.util.Iterator;

/**
 * Convert an HTTP header to a JSONObject and back.
 * 
 * @author JSON.org
 * @version 2
 */
public class HTTP {

	/** Carriage return/line feed. */
	public static final String	CRLF	= "\r\n";

	/**
	 * Convert an HTTP header string into a JSONObject. It can be a request header or a response header. A request
	 * header will contain
	 * 
	 * <pre>
	 * {
	 *    Method: &quot;POST&quot; (for example),
	 *    &quot;Request-URI&quot;: &quot;/&quot; (for example),
	 *    &quot;HTTP-Version&quot;: &quot;HTTP/1.1&quot; (for example)
	 * }
	 * </pre>
	 * 
	 * A response header will contain
	 * 
	 * <pre>
	 * {
	 *    &quot;HTTP-Version&quot;: &quot;HTTP/1.1&quot; (for example),
	 *    &quot;Status-Code&quot;: &quot;200&quot; (for example),
	 *    &quot;Reason-Phrase&quot;: &quot;OK&quot; (for example)
	 * }
	 * </pre>
	 * 
	 * In addition, the other parameters in the header will be captured, using the HTTP field names as JSON names, so
	 * that
	 * 
	 * <pre>
	 *    Date: Sun, 26 May 2002 18:06:04 GMT
	 *    Cookie: Q=q2=PPEAsg--; B=677gi6ouf29bn&amp;b=2&amp;f=s
	 *    Cache-Control: no-cache
	 * </pre>
	 * 
	 * become
	 * 
	 * <pre>
	 * {...
	 *    Date: &quot;Sun, 26 May 2002 18:06:04 GMT&quot;,
	 *    Cookie: &quot;Q=q2=PPEAsg--; B=677gi6ouf29bn&amp;b=2&amp;f=s&quot;,
	 *    &quot;Cache-Control&quot;: &quot;no-cache&quot;,
	 * ...}
	 * </pre>
	 * 
	 * It does no further checking or conversion. It does not parse dates. It does not do '%' transforms on URLs.
	 * 
	 * @param string
	 *            An HTTP header string.
	 * @return A JSONObject containing the elements and attributes of the XML string.
	 * @throws JSONException
	 */
	public static JSONObject toJSONObject(final String string) throws JSONException {
		final JSONObject o = new JSONObject();
		final HTTPTokener x = new HTTPTokener( string );
		String t;

		t = x.nextToken();
		if ( t.toUpperCase().startsWith( "HTTP" ) ) {

			// Response

			o.put( "HTTP-Version", t );
			o.put( "Status-Code", x.nextToken() );
			o.put( "Reason-Phrase", x.nextTo( '\0' ) );
			x.next();

		} else {

			// Request

			o.put( "Method", t );
			o.put( "Request-URI", x.nextToken() );
			o.put( "HTTP-Version", x.nextToken() );
		}

		// Fields

		while ( x.more() ) {
			final String name = x.nextTo( ':' );
			x.next( ':' );
			o.put( name, x.nextTo( '\0' ) );
			x.next();
		}
		return o;
	}

	/**
	 * Convert a JSONObject into an HTTP header. A request header must contain
	 * 
	 * <pre>
	 * {
	 *    Method: &quot;POST&quot; (for example),
	 *    &quot;Request-URI&quot;: &quot;/&quot; (for example),
	 *    &quot;HTTP-Version&quot;: &quot;HTTP/1.1&quot; (for example)
	 * }
	 * </pre>
	 * 
	 * A response header must contain
	 * 
	 * <pre>
	 * {
	 *    &quot;HTTP-Version&quot;: &quot;HTTP/1.1&quot; (for example),
	 *    &quot;Status-Code&quot;: &quot;200&quot; (for example),
	 *    &quot;Reason-Phrase&quot;: &quot;OK&quot; (for example)
	 * }
	 * </pre>
	 * 
	 * Any other members of the JSONObject will be output as HTTP fields. The result will end with two CRLF pairs.
	 * 
	 * @param o
	 *            A JSONObject
	 * @return An HTTP header string.
	 * @throws JSONException
	 *             if the object does not contain enough information.
	 */
	public static String toString(final JSONObject o) throws JSONException {
		final Iterator<String> keys = o.keys();
		String s;
		final StringBuffer sb = new StringBuffer();
		if ( o.has( "Status-Code" ) && o.has( "Reason-Phrase" ) ) {
			sb.append( o.getString( "HTTP-Version" ) );
			sb.append( ' ' );
			sb.append( o.getString( "Status-Code" ) );
			sb.append( ' ' );
			sb.append( o.getString( "Reason-Phrase" ) );
		} else if ( o.has( "Method" ) && o.has( "Request-URI" ) ) {
			sb.append( o.getString( "Method" ) );
			sb.append( ' ' );
			sb.append( '"' );
			sb.append( o.getString( "Request-URI" ) );
			sb.append( '"' );
			sb.append( ' ' );
			sb.append( o.getString( "HTTP-Version" ) );
		} else {
			throw new JSONException( "Not enough material for an HTTP header." );
		}
		sb.append( CRLF );
		while ( keys.hasNext() ) {
			s = keys.next().toString();
			if ( !s.equals( "HTTP-Version" ) && !s.equals( "Status-Code" ) && !s.equals( "Reason-Phrase" )
			        && !s.equals( "Method" ) && !s.equals( "Request-URI" ) && !o.isNull( s ) ) {
				sb.append( s );
				sb.append( ": " );
				sb.append( o.getString( s ) );
				sb.append( CRLF );
			}
		}
		sb.append( CRLF );
		return sb.toString();
	}
}
